We report a patient with a relapsing form of acute brainstem encephali
tis. Pathological examination demonstrated necrotizing encephalitis in
the cerebral cortex and, more pronounced, throughout the diencephalon
, as well as in the pes pontis. Neurons and glial cells in the cerebra
l cortex and brainstem contained herpesvirus antigens. The clinical in
terrelationship of brainstem encephalitis, Miller Fisher syndrome and
Landry-Guillain-Barre syndrome is discussed.